Scientists studying fetal development have documented four common behaviors of unborn humans in the womb. These behaviors have been labeled as quiet sleep, active sleep, quiet awake, and active awake. However, there may be a fifth behavioral state that occurs during the third trimester.
Ultrasound videos have shown that fetuses appear startled in response to low-decibel noise transmitted through the mother’s abdomen. The fetuses display the characteristics of crying – mouth open, tongue depressed, taking several irregular breaths before exhaling. Researchers theorized that the fetuses may be practicing the crying behavior that they will perfect outside the womb.
Getting ready to cry for real:
- In an issue of the Archives of Disease in Childhood, researchers describe stumbling upon the finding while studying the effects of tobacco and cocaine use by mothers during pregnancy.
- The researchers ruled out the possibility that the behavior was specific to substance abuse. Fetuses carried by both users and non-users exhibited the same type of crying behavior.
- This behavior may have significant developmental implications, because crying requires various motor systems, and the recognition that a fetus can respond appropriately to a negative stimulus.
